Sheet separating mechanism



. Dec. 29, 1936. K. BLAETTNER SHEET SEPARATING MECHANISM Filed Dec. 24. 1955 WWW;

By -Wa-W Patented Dec. 29, 1936 Application Decemberlfi l, i935, Serial No. sense In Germany rchfi, 1935 '2 Claims. Eoi. arr-3s The invention refers to a method and apparatus for the separation of the front edge to be brought against the lay marks of a printing machine or the like, of, the second sheet from the a top of a pile consisting of mutually overlapped sheets, from the top sheet of this pile which is being drawn oil.

With machines which dealwith the material to be printed, in the form of sheets, it is known in addition to feeding the sheets in separate sequence, also to feed the sheets in a piled overlapped form, which method is being more and more adopted in order to comply with the increased requirements in output. In any case, each separate sheet before it can be printed, must in its course be held stationary for a short time and be adjusted for the purpose of being accurately gripped, whereupon it is seized by suitable members and can be carried forward.

pose are in known manner arranged above the sheet moving towards the printing machine, these mechanisms must wait until the sheet just moving forward leaves the one under it free in order, on their part, to be able to exert their purpose on the next sheet. If, on the contrary, these mechanisms are'arranged below the part of the paper, then an increase of output is attained in so far as the mechanisms serving for retaining and ad-. justing the sheet as also for its feeding forward,.,

may deal with the next sheet before the previous onto the lay mark so that the said second sheetis carried away with the top sheet over the mark.

chanical properties of the paper to be dealt with in the printing industry, the hitherto proposed apparatus for the laying on and adjustment of the separate sheets in the case of feed by overlapped sheets have not proved themselves re- I liable. It is a question here of a phenomenon which with the individual feed hitherto usual of the sheets to be printed could not take place.

With the earlier kind of single sheet laying on,

no sheet could pass the lay marks, since it was If now, the mechanisms provided for this pur- With the many difierent thicknesses andme- I always possible.to take the sheet to ,be laid on in guide members arranged above and below the lay mark when approaching it, which guide mem-, bers approached each other more and more, and

the outlet end of which was closed by the lay mark. Each sheet was carried to a certain extent into a funnel-shaped gap out of which there was no escape and which delivered the sheet with-,

out fail on to the lay marks.

.With overlapped sheet sequence, on the con-Y form an uninterrupted paper web which cannot be interrupted at the top.

, It may consequently happen at any time that the following lower sheet is drawn with the sheet to be fed forward, over the lay mark and does not come to the proper laying on position at all. It then passes uncontrolled into the machine and causes all kinds of dimculties and finally the stoppage of the machine.

These defects are obviated by the method and apparatus according to the present invention.

The invention consists in the front part of the overlapped sheet being pressed or introduced by a pressing member acting on the top sheet into a depression formed in or on the feed table, and by the front edge of the overlapped sheet being defiected fro'm the path of the sheet running off and being carried with certainty under the overmark, that is, the front or lay mark provided with a projecting retaining holder.

In this, the pressing member necessary for carryingoutthe process can be constructed as a roller which presses the sheet downward in waveform and there may be provided a recessed part in or on the feed table underneath the pressing member.

The same effect may be attained in combination with the pressing member by the arrangement of a mushroom-sectioned strip, a projection or a number of projections on the feed table, these being above the level of the feed table. These mushroom-shaped strips or projections may be movably and adjustably arranged in the feed table and the lay marks on the feed table may also be arranged so that they may be raised.

In Figures 1 and 2 of the accompanying drawing is shown by way of example an apparatus for carrying out the method according'to the" invention, in different constructions, in which:

Figure 1 shows the construction with a pressure roller and recessed part in the feed table, and

Figure 2 the same with a roller and mushroomsectioned strip.

As will be seen from the Figures 1 and 2 of the drawing, such an action takes place on the top sheet I by means of a pressing member and porarily lifted or be left permanently in the position shown, or finally be adjusted in height according to the material.

The front part of the overlapped sheet 2 is pressed into this recessed part by the roller 5 made as the pressing member, and thus its front edge is deflected from the path of the sheet I running off after being seized by the gripping device 4, and is carried with certainty under the over-mark 3.

In order to ensure an introduction of the front edge of the sheet 2 under the over-mark 3, the latter may be temporarily raised by its edge 9 parallel to the feed table 8, until the front edge has reached the-over-mark 3. The mark 3 must then again be lowered to a small distance from the feed table 8. This distance must not be greater than the thickness of two or three sheets in order to avoid a rolling up or bending over of the front edge of the sheet.

When the sheet I has been drawn a certain distance in the direction of the arrow by the rocking gripper or by the feed roller, the sheet 2 may be brought up to the lay mark 3 which is at the same time constructed as the overmark, and be adjusted. In the pictorial representation, the function of the lay mark is assigned to the vertical edge, leading down- Ward to the surface 9, and which rests on the table plate 8. This may, as a' matter of fact, be used therefor, as long as no adjustment in the direction of the running of the sheet is necessary. With simpler printing and copying machines, this is the case. In larger printing machines, however, there are provided stationary butadjustably lay marks, the striking surface of which for the sheets approximately coincides with the above characterized edge of the overmark. The overmarks 3 are then arranged close to" or between the lay marks.

In order not to allow the pressing member or roller 5 to bear continuously on the upper sheet and thus to produce unnecessary friction, it is preferably only brought into operation, that is, pressed on to the sheet, when the front edgeof the sheet 2 is close to the lay mark, which may be attained by the temporary or periodic pressing down of the roller, of a rocking lever orthe like in a known manner. too heavily on the sheet I, so that the sheet 2 carried along is not brought by friction and by the greater speed of the sheet I too sharply against the lay mark.

What I claim is:

1. In a printing process, or the like, a method for the separation of the front edge of the second sheet from the top of a pile consisting of mutually overlapped sheets from the top sheet which is being drawn off this pile, consisting in advancing the two top sheets until the top sheet alone has passed beyond an overmark, and so pressing the front part of the overlapped sheet second from the top by a pressing member moved against the upper sheet into a recess in or on the feed table, that the topmost sheet undergoes a harmless bending, whilst the front edge of the overlapped sheet is deflected from the path of the topmost sheet running off and is brought with certainty below a lay mark provided with a holding down member.

2. In a printing press, or the like, with a feed of successively underlapped sheets, a sheet separating apparatus comprising a lay mark, an overmark, and a pressing member adapted to deflect a gripped sheet and the front edge of the second sheet at such a time as the gripped sheet is passing around the overmark and the front edge of Finally, it should not bear the second sheet has not reached the overmark,

the feed table has a recessed part below the pressing member.

4. An apparatus according to claim 2 wherein the pressing member is in the shape of a roller.

5. An apparatus according to claim 2 wherein the feed table is substantially flat and is provided with a projecting guide adapted to raise. the sheets from the table to enable the pressing member to operate upon them.

6. An apparatus according to claim 2 wherein the feed table is substantially flat and is provided with a removable and adjustable projecting guide adapted to raise the sheets from the table to enable the pressing member to operate upon them.

'7. An apparatus according to claim 2 wherein the lay mark and the overmark are a unitary structure adapted to move from an operative to an out-of-the-way position.

KARL BLAE'I'INER. 

